Reduce image file size while preserving quality. All processing happens in your browser.
or click to browse your files
Reduce image file sizes in three easy steps — no software installation required.
Drag and drop your image file into the upload area or click the button to browse your device. We support JPG, PNG, and WEBP formats for maximum compatibility with any workflow.
Choose a quality preset or use the custom slider to find the perfect balance between file size and visual quality. Preview the result in real time before committing to any changes.
See exactly how much space you saved with the size comparison display. Click the download button and your compressed image is saved directly to your device, ready to use anywhere.
A smarter, faster, and more private way to optimize your images for the web and beyond.
Compress as many images as you need with no daily limits, no credit card, and no premium upsells. Every feature is available to every user at zero cost.
Your images never leave your device. All compression happens locally in your browser using JavaScript. We have zero access to your files, metadata, or personal data.
Fine-tune compression with preset quality levels or a custom slider. Preview results in real time and find the ideal trade-off between file size and visual clarity for your specific use case.
Compress images one after another with consistent settings. Upload, compress, download, repeat. Each file takes just seconds to process on any modern device.
Supports the three most popular web image formats: JPG for photographs, PNG for graphics with transparency, and WEBP for next-generation web optimization.
Your compressed images are clean and untouched. We never add logos, watermarks, or branding of any kind to your output files.
Everything you need to know about reducing image file sizes without sacrificing quality.
Image compression is the process of reducing the file size of a digital image while attempting to maintain an acceptable level of visual quality. Every time you take a photo with your phone or save an image from a design tool, the resulting file contains a vast amount of data describing every pixel's color, position, and transparency. For a single high-resolution photograph, this can easily exceed 5 to 10 megabytes. When you are building a website, sending images by email, or uploading photographs to social media, these large file sizes slow down page load times, consume bandwidth, and eat into storage quotas. Image compression solves this problem by applying algorithms that reduce the amount of data needed to represent the same visual content. Faster websites rank higher in search engines, use less mobile data, and deliver a better experience to visitors. Studies consistently show that even a one-second delay in page load time can reduce conversions by up to seven percent, making image optimization one of the highest-impact performance improvements you can make.
There are two fundamental approaches to image compression: lossy and lossless. Lossy compression works by permanently removing data that the human eye is unlikely to notice. The JPEG format, for example, uses a technique called discrete cosine transform to discard high-frequency color information that contributes very little to the perceived image quality. At a quality level of 80 percent, a typical JPEG photograph can be reduced to one-fifth of its original size with virtually no visible difference. The trade-off is that once data is discarded, it cannot be recovered. Lossless compression, on the other hand, reduces file size by finding more efficient ways to encode the same data without discarding anything. The PNG format uses lossless compression by default, which is why PNG files tend to be larger than JPEGs for photographs but are ideal for graphics, screenshots, and images with text where every pixel matters. WEBP, developed by Google, supports both lossy and lossless modes, offering excellent compression ratios for either use case and is increasingly adopted as the preferred format for modern web development.
Selecting the correct image format before compressing is just as important as the compression itself. Use JPEG for photographs, portraits, landscapes, and any image with complex color gradients. JPEG excels at representing the subtle tonal variations found in real-world scenes, and its lossy compression algorithm is specifically optimized for photographic content. Choose PNG when you need transparency, sharp edges, or pixel-perfect accuracy. PNG is the best choice for logos, icons, screenshots, diagrams, and any graphic that contains text or clean geometric lines. Because PNG uses lossless compression, the output will always be an exact reproduction of the original, making it essential for professional design workflows. WEBP is the modern all-rounder. It produces files that are 25 to 35 percent smaller than equivalent JPEGs and up to 26 percent smaller than equivalent PNGs, according to Google's own benchmarks. If your target audience uses modern browsers, WEBP delivers the best combination of quality and file size for virtually every use case.
Optimizing images for the web involves more than just running them through a compressor. Start by resizing images to the dimensions they will actually be displayed at. There is no benefit to serving a 4000-pixel-wide image in a container that is only 800 pixels wide. Use the Max Dimension setting in our tool to automatically scale down oversized images during compression. Next, consider the quality setting carefully. For hero images and product photos where visual quality is paramount, use 80 to 90 percent quality. For thumbnails, background textures, and decorative elements, you can safely drop to 60 to 70 percent without any noticeable loss. Always preview the compressed result before downloading to confirm the output meets your standards. For websites, aim to keep individual image files under 200 kilobytes whenever possible, and total page image weight under one megabyte. Combine image compression with responsive images using the srcset attribute to serve appropriately sized images to different devices, further reducing bandwidth consumption on mobile networks.
To achieve the greatest file size reductions, combine multiple strategies. First, crop your image to remove unnecessary areas before compressing. Every pixel in the image contributes to the file size, so removing borders, whitespace, or irrelevant background content can make a significant difference. Second, reduce the color palette when appropriate. Many graphics and illustrations use only a handful of colors, and reducing the color depth can yield dramatic savings without any visible impact. Third, strip unnecessary metadata. Digital camera images often contain extensive EXIF data including GPS coordinates, camera settings, and embedded thumbnails that add kilobytes to every file. Our compression tool automatically handles this for you, producing clean output files with minimal overhead. Finally, if you are compressing images for email attachments or messaging apps, consider using a lower quality setting since these platforms often re-compress images anyway. Starting with a well-optimized file means the final result will look better even after additional platform compression. By following these strategies and using ConvertKr's image compressor regularly, you can typically reduce your total image storage by 50 to 80 percent while maintaining excellent visual quality across all of your digital content.
Common questions about compressing images with ConvertKr.
ConvertKr Image Compress supports the three most popular web image formats: JPG (JPEG), PNG, and WEBP. These cover the vast majority of images used on websites, in email, and across social media platforms.
Image compression involves a trade-off between file size and visual quality. At higher quality settings (80-95%), the difference is virtually imperceptible to the human eye. You can preview the compressed result and adjust the quality slider until you find the perfect balance for your needs.
You can compress images one at a time with consistent settings. Upload an image, set your desired quality level, download the compressed version, then upload the next file. Each compression takes only a few seconds.
Since all compression happens in your browser, the practical limit depends on your device's available memory. Most modern computers, tablets, and smartphones handle images up to 50 MB without any issues.
Yes. All image processing happens entirely in your browser using client-side JavaScript. Your files are never uploaded to our servers. We cannot see, access, or store your images. Once you close the browser tab, all data is gone.
Absolutely. ConvertKr's image compressor is fully responsive and works on smartphones, tablets, laptops, and desktops. It is compatible with Chrome, Safari, Firefox, Edge, and all modern mobile browsers.
JPG uses lossy compression, which permanently removes imperceptible data to achieve smaller file sizes. It is ideal for photographs. PNG uses lossless compression, preserving every pixel exactly. It is better for graphics, logos, and images with transparency or sharp text.
Image compression algorithms analyze pixel data and remove redundancies. Lossy methods like JPG discard information the human eye is unlikely to notice, such as subtle color variations. Lossless methods like PNG find more efficient ways to encode the same data. Both approaches reduce file size, but lossy compression achieves greater reductions.
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